Apparatus for treating and diffusing pyrethrum



Jam. 5, 1937.

W. S. BURGESS El" AL APPARATUS FOR TREATING AND DIFFUSING PYRETHRUM 2 Sheets-Sheet 1 Filed Sept." 11, 1933 IN VEN TOR EWa/fe/r; 12022666 3 B 0 0 6 A TTORNE Y:

45 the said spray head il.

leading up from the interior of the container 18 iatented Jan. 5, 1937 "APPARATUS FOR. TREATING AND DIFFUSING PYRETHRUM Walter S. Burgess and Earl K. Golley, Benton Harbor, Mich, assignors to The 0. & W. Thum Company, Grand Rapids, Mich.

UNlTEDfSTATES Application Septemberll, 1933, Serial No. 688,907

1 Claim. (01. 299-87) This application is a division of our patent applicationSerial No. 660,010 filed-March 8, 1933, which application is a continuation in part of our patent application Serial No. 563,312, filed September 17, 1931.

The objects of this invention are:

First, to provide an, improved apparatus for treating pyrethrum with steam and diffusing the same into space.

Second, to providesuch an improved apparatus that thoroughly mixes pyrethrum solution and steam inthe proper proportion for best killing of insects and diffuses the mixture in an infested area. l 1

Further objects relating to details of construction and operation will appear from the detailed description to follow. A preferred form of the apparatus for carrying out our methodis illustrated in the accompanying drawings, in which:

Fig. ,1 is a detail side elevation view of our complete'apparatus ready to plug inon an electric lamp socket.

Fig. Zis a. plan view Fig.3 is an enlarged .detail vertical sectional 25 view through our complete apparatus.-' r

Fig. 4 is. a vertical sectional view through the spray head of the difiusing and distilling-apparatus, taken on line 4-4 of Fig. 5.

Fig. 5 is a detail transverse sectional View: on-

30 line 5-5 of Fig; 4. l

Fig. 6 is a detail view oithe head as constructed without adjustable feature.

The parts will be identified by their numerals of reference which are the same in all the views;

glass jar. sealed thereon. posed in the main reservoir to heat the water 4 contained therein. 5 ;is the electric connection 40 for the unitxconnected to the cap or cover 2. 6

is the filler plug. .1 is the relief valve. 8 is the container-for apyrethrum concentrate 9. I0 is the connectiontothe spray or atomizer head ll leading from the steam. spaceof'the reservoir'to I2 is the supply "pipe to supply liquid concentrate .to the head ll.

- The spray head .I I oi brass is of considerable mass to accumul "te heat. I Ste'amdelivers into a 5 chamber J3 thereinfrom which delivers a steam jet '14 out throughthe spray aperture l5 from themixin'g' chamber l6.- {Iube l2 leads up'into the-chamber- I'Lin' the spray head, which is connected by the Giving attentionfto certain details, thechamher It is iormed by'a cap I61 which is screw- 3 threaded onto a. nipplefl l I which. projects slightly in a nozzle at 2., The bo re I4 is drilled with a a0 number'BBfL 1 ill andisf 031 of'an inch in diameter.

of the cap part detached.

l is the main reservoir, preferably a strong *2 is the metal cap screw-threaded and 3 isan electric heater unit disby the steam as it passes to the'spray head spray nozzlefll to the mixing sure and the temperature of the steam is consequently considerably above boiling point, or 212 F. The head ll presenting a considerable mass of metal, is consequently quite strongly heated by the hot steam (and is a; heat reservoir) ,--to just what temperature it is impossible to estimate, but the relations of the parts are givenand the temperature resulting is high enough to do the work. Whilethe temperature certainly very closely approaches the boiling point,

- it in operation in no way damages the pyrethrins or pyrethrum solution or concentrate. The solution or concentrate 9 is a kerosene solution made from pyrethrum flowers and kerosene or mineral oil and is a usual manufactured product known .by that name and commercially sold as pyrethrum concentrate. This works exceedingly well with this apparatus. The best authorities at the present time assert'that the pyrethrins oractive principle ofpyrethrum' are not soluble in water to any appreciable extent.

While the pyrethrum concentrate, which theoretically contains a very small percentage of the pyrethrins or active principle, gives satisfactory results under our process, we are aware that. a

much weakersolution can be made-use of with corresponding results. In place" of kerosene or mineral oil as a solvent, we are very clear that any effective solvent for the pyrethrum will be effective in this position, it being desirable that the solvent be volatile at=a different temperature from the water.

It is our belief that in the operation of this apparatus an attenuated stream of the dissolved pyrethrins or pyrethrum principle is preheated and is taken up bya comparatively small quantity of thesteam' in the mixing chamber l6 wherethe I high temperature and the steam have the effect of freeingthe active principle, which is thenprojected with the steam jet through the bore :15 into the atmosphere where thewhole mass discharged assumes a feather-like appearance like steam jettingirQm' the nozzleof a teakettle.

With the apparatus as we have it, this fine jet isprojected into the atmosphere .four feet or more and the feather appearance disappears.

at thatl oint, but the atmosphere of the room;

particularly where it is distributedf I appears shortlyto contain a cloud which is certainly irn pregnated with the, pyrethrum material v As a gas), and

that a temperature appoint of water (212 F.)

probably causes a chemical breakdown in the.

pyrethrins. We do not know that the pyrethrins are not broken down into some other material by the action of our apparatus, but if so it is a material apparently that is as toxic to insect life as the pyrethrins and apparently even more so. That is, there may be a special development of pyrethrum active principle or a new product or compound. We have stated our theories in this matter so that they may be understood.

In the operation of'our process and apparatus for the destruction of roaches, the material at once penetrates into all recesses and crannies that have any air space connection to the body of the room. This is done where no pressure has been exerted by the spray from the apparatus. It is simply done by the diflusion. In the case of a metallic protecting shell or hell of an electric fixture, if there are roaches behind it, they at once come out, being driven out by the action of the material which has permeated through the narrow space accessible. Roaches around a door casing entirely concealed from view at once come out. Roaches behind baseboards at a point where no possible visible vapor has reached, at once come out into the open and die. We refer to this as evidence of the fact that what we have produced is a gas or a gaseous vapor having the diffusion properties of a gas. The minute quantity-which does the work makes it impossible of any effective determination or chemical analysis that we have been able to accomplish or that we have been able to find out how to accomplish.

We wish to distinguish our apparatus and process from steam atomizers and their action. The object of a steam atomizer is to make use of the pressure and volume of the steam to disintegrate a liquid. The liquid, unless it is quite highly volatile, is simply broken up into particles, that is, atomized, and the steam may serve to some extent as a carrier. However, the steam usually has the same eil'ect as a jet of air and is not quite so efllcient because it immediately condenses.

We also wish to distinguish our apparatus and process from the usual construction of spray guns which are piston air pumps which deliver a jet of air into an atomizer head and atomize any product in the usual way of atomizers. For the past ten years they have been used and demonstrated as of very high efllciency in the matter of household sprays. Such spray guns, however, are only partially eflicient. It is necessary to direct the spray into any cranny and the usual directions are to do this for the treatment of roaches and to spray the material diand also to claim the rectly onto the roaches when they will hide and die. Our structure has no such limitation because where a room is infested with roaches and is treated with our apparatus, they come out from the crannies and in a case of bad infestation, the floor of a room will be completely cov. ered with dead roaches so that very frequently it is not possible towalk across the floor of such a room without crushing numerous roaches under the feet.

To compare with the action of a spray gun, our apparatus and process are yery eifective where an oil solution containing one patent. of the active principle of pyrethrum is made use of. Our experience demonstrates that with such a solution, a substantial eflect is obtained by evaporating and converting one ounce of water for an ounce of the solution; that the eil'ectlveness increases to a maximum when we convert three ounces of water to steam in the treatment of one ounce of 1% solution of pyrethrum;

that very good work is done when 6 ounces of water is converted to steam for each ounce of 1% pyrethrum solution. This shows a wide range of efliclency for the apparatus and process.

With this treatment, one ounce of 1% solution of pyrethrum, a usual strength of pyrethrum concentrate, will, when treated with three ounces of water converted to steam, that is approximately, 5100 volumes of steam to the ounce of concentrate which is substantially equal to of water, or approxivolume of active principle, eflfectively treat a. room of 10,000 cubic feet capacity, that is, a room 10 x 10 x 100. It will be seen that in each cubic foot of room treated, if the distribution is perfect, there will be one millionth part of an ounce of the active principle of pyrethrum.

The treatment for the destruction of moths needs to be exceedingly thorough and repeated at intervals of a few days for several times, because the treatment is not eifective in destroying the insects eggs and moths are, to quite an extent, protected by whatever they are destroymg.

We have indicated precisely the dimensions of our apparatus. This apparatus has been demonstrated as of the highest eillciency in a year's commercial exploitation, so that in discussing the action of our device, we arev not discussing a theory but actual practice.

We desire to claim the apparatus specifically same broadly.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

In a difluser or the like, a vapor discharge, a liquid 8. vaporizer having receptacle external of said vaporizer and;a tube suspended in said WALTER s. amass. EARL KL com. 

